• Title/Summary/Keyword: 수밀

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A Case of Underwater Blasting Performance Using a Structural Underwater Charging System (수중발파용 구조체를 이용한 수중발파 시공사례)

  • Kim, Young- Keun;Kim, Seung-Kon
    • Explosives and Blasting
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    • v.36 no.2
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    • pp.27-35
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    • 2018
  • This study introduces a suggested underwater blasting method in contrast with conventional underwater blasting methods which adopt the drilling and charging procedures by divers. A structural underwater charging system makes it possible to drill into underwater bedrock and charge explosives on the deck of barge ship. The applicability and effectiveness of the suggested method was experimentally approved by comparing with a kind of underwater charging system as a conventional underwater blasting method.

Watertightness Property Evaluation of Rain-Block System (개폐식 대공간 구조물에서 지붕 맞댐부 우수차단 시스템의 수밀성 평가에 관한 연구)

  • Kim, Yun-Ho;Baek, Ki-Youl;Kim, Jong-Su;Lee, Sun-Gyu;Oh, Sang-Keun
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2010.05a
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    • pp.13-16
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    • 2010
  • This study is an Investigation on the Watertightness Properties of Rain-Block System on the Sliding-Roof Joint of Large-Span Membrane Structures. In this experimental, we test the watertightness performance of joint part of sliding door in roof of large span membrane structure(for pilot project) under environment of rain and wind. A shape of rain water blocking systems of joint part in sliding door verifies the defects and effects of water leakage prevention in precipitation with the wind conditions. For obtaining watertightness of large span membrane structures, it is necessary quality of joints and performance, and quality of membrane material of a retractable roof as well as a closed roof. Also, for obtaining quality in joints, it is essential to make a watertightness guideline for design of large-span membrane.

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Failure analysis on the phenomenon of water condensing of automotive head lamp assembly (자동차용 head lamp의 수밀원인 분석)

  • Cho, Young-Jin;Jeon, Jong-Soo
    • Proceedings of the KSME Conference
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    • 2008.11a
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    • pp.1349-1354
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    • 2008
  • In this study, we try to find the root cause of water condensing failures in a headlamp using chemical and mechanical analysis. Through the surface inspection by OM, SEM and CT, it was found that water infiltrate into the headlamp through hotmelt adhesive debonding part caused by adhesion force degradation and poor quality. IR spectra shows that adhesion force degradation are characterized by increase of some functional group(1742, 1710, 1649, 1016). Through the ESPI measurement, it is turned out that bonding structural change by thermal expansion and degradation of adhesive can be the cause of void generation. So it is recommended that cooling passage and the bonding part should be redesigned to give a guarantee of less thermal stress and high adhesion quality.

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A Study on the Watertightness of Shotcrete with Watertightness Materials (수밀성 재료에 의한 숏크리트의 수밀성에 관한 연구)

  • Kang, Hyun-Ju;Song, Myong-Shin;Lee, Sang-Kook
    • Journal of the Korean Ceramic Society
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    • v.45 no.6
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    • pp.350-357
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    • 2008
  • The use of shotcrete-sprayed concrete for the support of underground excavations was pioneered by the civil engineering. Now, for the nuclear wastes disposal plant in our country, watertightness of shotcrete is one of the very important properties. This study evaluated the watertightness of shotcrete using cement mineral accelerator with watertightness materials for the long-term watertightness. In this study, for improvement of watertightness of shotcrete, it used two types of obtainable at a store. Watertightness tests of shotcrete were performed the water absorption coefficient, permeability, porosity and hydrates variation. In a shotcrete containing watertightness materials, watertightness of shotcrete was improved about $15%{\sim}65%$ rather than plain shotcrete.

Improvement of Watertightness Evaluation Method in Waterproof Membrane (복합계 멤브레인 방수층의 수밀성 시험 평가방법 개선방안 연구)

  • Kim, Meong-Ji;Seon, Yun-Suk;Kim, Soo-Yeon;Oh, Sang-Keun
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2018.11a
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    • pp.50-51
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    • 2018
  • Although the introduction of new materials and new construction methods and overseas materials has become more active due to the diversification of the construction market, the quality standards of waterproofing methods in Korea are insufficient. In particular, the quality control standard is applied to the KS F 2622:08 (Membrane Waterproofing layer performance test method), which is the existing standard, to prepare standards for quality control of waterproof materials, which is increased in Korea.

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An Experimental Study on Improving Water Tightness of Concrete Surface Applied High Growth Organic Crystalization Material (고성장 유기결정체의 성장 특성을 이용한 콘크리트 표층부의 수밀성 개선에 관한 연구)

  • Song Je-Young;Kang Hyo-Jin;Oh Sang-Keun
    • Proceedings of the Korea Concrete Institute Conference
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    • 2004.11a
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    • pp.817-820
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    • 2004
  • Our country was much developments in change of construction environment along with fast economy development. But, various problems that must think in problem of safety and quality were appeared. Constructions which build through rapid economy development are getting many social criticisms to problem of crack and water leakage at use process. Is situation that huge repair expense to cure this is engaged. Safety problem of construction is indicated socially through various media mediums again.

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A Study on the Flexural Rigidity Change according to Quantities Characteristics of Waterproof Admixture for Concrete (콘크리트용 수밀 혼화재 첨가량에 따른 휨 강도 변화추이 연구)

  • Choi, Su-Young;Park, Jin-Sang;Kim, Dong-Bum;Park, Wan-Goo;Kim, Byoung-Il;Oh, Sang-Keun
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2017.11a
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    • pp.128-129
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    • 2017
  • Concrete properties alone cannot provide satisfactory waterproof performance because concrete can generate cracks due to possible problems in design, construction and curing process, and various environmental factors. Therefore, concrete structures require installing waterproofing layers for concrete protection and various types of construction methods are currently being applied. The purpose of this study is to investigate the concrete strength changes when waterproofing admixtures are mixed into the concrete. The results of flexural strength testing confirmed that the initial strength of concrete specimens with the admixtures was lower than that of the concrete specimen without the admixture based on different curing periods.

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